On a topographic map, the disconnected short lines used to show the steepness and direction of slope are called what?

Introduction / Context:
Map reading skills are very important in geography and earth science exams. Various symbols and line types are used to represent relief and landforms on a map. While continuous contour lines are familiar to most students, older or specialised maps sometimes use disconnected short lines to show slopes and relief. This question focuses on identifying the correct term for those disconnected lines that indicate slope steepness and direction on a topographic map.

Given Data / Assumptions:

• The context is a topographic or relief map.
• The map uses disconnected short lines to represent slope.
• The options given are bench marks, contours, form lines, and hachure.
• Standard cartographic terminology is assumed.

Concept / Approach:
Contours are continuous lines that join points of equal elevation and are widely used in modern maps. Bench marks are specific points on a map whose exact elevation is known and marked, not a pattern of lines. Form lines are approximate contour-like lines used when precise surveying data is not available. Hachures, on the other hand, are short disconnected strokes or lines drawn down the slope, thicker or closer together for steeper slopes. Therefore, when the question refers specifically to disconnected lines shown for slope, the correct technical term is hachure.

Step-by-Step Solution:

Verification / Alternative check:
A quick memory check is that hachure shading is often used in older atlases to give a shaded appearance to hills and mountains, with small strokes aligned down the slope. Modern atlases may still describe this technique when explaining historic mapping methods. Since no other mapping term in the options fits the description of disconnected slope lines, confirming that hachures are used for this purpose validates the choice.

Why Other Options Are Wrong:

• Bench marks: Represent specific surveyed points with known elevation values and are shown by symbols or numbers, not by a series of disconnected short lines.
• Contours: Continuous lines joining places of equal altitude, not fragmented strokes. They represent height levels rather than slope direction through short dashes.
• Form lines: Approximate, less accurate contour-like lines, but still drawn continuously and not as disconnected short strokes.

Common Pitfalls:
Students often confuse any line related to relief with contours, leading them to choose contours even when the question clearly states "disconnected." Another common pitfall is to ignore the historical context of mapping techniques such as hachuring, which may not be used in all modern maps but remain important in exam syllabi. Misreading the word as "hatch" or associating it only with shading can also cause confusion. Carefully focusing on the key phrase "disconnected lines" helps avoid these errors.

Final Answer:
The disconnected short lines drawn on a map to show the steepness and direction of slope are known as Hachure.